Bulletin of Entomological Research (2018) 108, 451-460

M.D. Cooling, B.D. Hoffmann, M.A.M. Gruber and P.J. Lester (2018)
Indirect evidence of pathogen-associated altered oocyte production in queens of the invasive yellow crazy ant, Anoplolepis gracilipes, in Arnhem Land, Australia
Bulletin of Entomological Research 108 (4), 451-460
Abstract: Anoplolepis gracilipes is one of the six most widespread and pestiferous invasive ant species. Populations of this invader in Arnhem Land, Australia have been observed to decline, but the reasons behind these declines are not known. We investigated if there is evidence of a pathogen that could be responsible for killing ant queens or affecting their reproductive output. We measured queen number per nest, fecundity and fat content of queens from A. gracilipes populations in various stages of decline or expansion. We found no significant difference in any of these variables among populations. However, 23% of queens were found to have melanized nodules, a cellular immune response, in their ovaries and fat bodies. The melanized nodules found in dissected queens are highly likely to indicate the presence of pathogens or parasites capable of infecting A. gracilipes. Queens with nodules had significantly fewer oocytes in their ovaries, but nodule presence was not associated with low ant population abundances. Although the microorganism responsible for the nodules is as yet unidentified, this is the first evidence of the presence of a pathogenic microorganism in the invasive ant A. gracilipes that may be affecting reproduction.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Philip J. Lester

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Anoplolepis gracilipes		Australia (NT+QLD)